Control Of Variable Displacement Vane Pump Used As Scavenge Pump

ABSTRACT

A system includes a first scavenge oil pump that draws oil from a first draw location within a vehicle according to a first variable displacement associated with the first scavenge oil pump. The first variable displacement is based on a first modified scavenge ratio assigned to the first scavenge oil pump. An oil pump control module determines a first scavenge ratio, determines a first scavenge ratio multiplier based on at least one of vehicle acceleration and vehicle orientation, and applies the first scavenge ratio multiplier to the first scavenge ratio to generate the first modified scavenge ratio.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 62/019,620, filed on Jul. 1, 2014. The disclosure of the above application is incorporated herein by reference in its entirety.

FIELD

The present disclosure relates to vehicle oil circulating systems, and more particularly to controlling variable displacement scavenge pumps in vehicle oil circulating systems.

BACKGROUND

The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

An internal combustion engine (ICE) of a vehicle typically includes an oil circulating system. The oil circulating system includes an oil pump that is mechanically connected to a crankshaft of the ICE. This connection assures that the oil pump is circulating oil to and from components of the ICE when the crankshaft is rotating (i.e. engine is operating). Output flow of the oil pump is related to the rotating speed of the crankshaft.

The oil pump draws oil from a sump (which includes an oil pan) to provide the oil to the components of the ICE. The oil flows from the components to return to the bottom of the oil pan. The return flow of the oil to the oil pan may be restricted or impeded during certain conditions or behavior of the vehicle, causing a “dry sump.” Accordingly, the vehicle may implement a dry sump lubrication system to “scavenge” oil from various locations within the ICE in the event of a dry sump. The dry sump lubrication system may include one or more pumps (e.g., scavenge pumps) that transfer the scavenged oil to a separate container (i.e., tank). Other pumps may draw the oil from the tank to pressurize the oil circulating system (e.g., supply pumps).

SUMMARY

A system includes a first scavenge oil pump that draws oil from a first draw location within a vehicle according to a first variable displacement associated with the first scavenge oil pump. The first variable displacement is based on a first modified scavenge ratio assigned to the first scavenge oil pump. An oil pump control module determines a first scavenge ratio, determines a first scavenge ratio multiplier based on at least one of vehicle acceleration and vehicle orientation, and applies the first scavenge ratio multiplier to the first scavenge ratio to generate the first modified scavenge ratio.

A method includes, using a first scavenge oil pump, drawing oil from a first draw location within a vehicle according to a first variable displacement associated with the first scavenge oil pump. The first variable displacement is based on a first modified scavenge ratio assigned to the first scavenge oil pump. The method further includes determining a first scavenge ratio, determining a first scavenge ratio multiplier based on at least one of vehicle acceleration and vehicle orientation, and applying the first scavenge ratio multiplier to the first scavenge ratio to generate the first modified scavenge ratio.

Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1 is a functional block diagram of an example engine system according to the principles of the present disclosure;

FIG. 2A is a functional block diagram of an example oil circulation control system including multiple scavenge pumps according to the principles of the present disclosure;

FIG. 2B is a functional block diagram of an example oil circulation control system including a single scavenge pump according to the principles of the present disclosure;

FIG. 3 illustrates an example oil circulation control system including a single scavenge pump for drawing pump from an oil pan according to the principles of the present disclosure;

FIG. 4 illustrates an example oil circulation control system including a multiple scavenge pumps according to the principles of the present disclosure;

FIG. 5 illustrates an example scavenge ratio multiplier map according to the principles of the present disclosure;

FIG. 6 illustrates an example single pump scavenge ratio control method according to the principles of the present disclosure;

FIG. 7 illustrates an example scavenge ratio control method for multiple pumps according to the principles of the present disclosure; and

FIG. 8 illustrates an example scavenge ratio control method using multiple scavenge ratio maps according to the principles of the present disclosure.

In the drawings, reference numbers may be reused to identify similar and/or identical elements.

DETAILED DESCRIPTION

An oil circulating control system according to the principles of the present disclosure controls a scavenge pump (or multiple scavenge pumps) according to one or more vehicle operation characteristics including, but not limited to, engine speed, engine load, vehicle acceleration (e.g., both lateral and longitudinal acceleration), vehicle yaw, and/or vehicle pitch. The vehicle operation characteristics may be indicative of the distribution of oil in the oil pan. For example, vehicle acceleration in the longitudinal direction may cause a larger portion of the oil in the oil pan to collect in a rear portion of the oil pan. Conversely, rapid vehicle deceleration in the longitudinal direction (e.g., vehicle braking) may cause a larger portion of the oil to collect in a front portion of the pan. Lateral acceleration in either lateral direction (e.g., caused by the vehicle turning) may cause a larger portion of the oil to collect in a respective opposite side portion of the pan.

Accordingly, the oil circulation control system controls the one or more scavenge pumps to draw oil from portions of the oil pan that, as indicated by the vehicle operating characteristics, are more likely to contain a larger portion of the oil. Further, the oil circulation control system controls the one or more scavenge pumps based on whether the vehicle operation characteristics indicate that a dry sump condition is likely. In other words, the scavenge pumps are controlled according to a desired scavenge ratio. For example, the one or more scavenge pumps are configured to allow variable displacement of the pumped oil (e.g., the scavenge pumps are operated according to electronically controlled displacement).

In this manner, the oil circulation control system controls respective scavenge ratios based on the vehicle operation characteristics. For example, when the vehicle operation characteristics indicate that a high scavenge ratio is not needed, the scavenge ratio is reduced, thus reducing the amount of excess air mixed with oil. Accordingly, aeration of the oil returned to the tank is reduced and power consumption of the scavenge pumps is reduced, resulting in reduced fuel consumption.

In FIG. 1, a functional block diagram of an exemplary engine control system 100 is shown. The engine control system 100 includes an oil circulating control system 104 that controls circulation of oil to and from components of an engine 108. The oil circulating control system 104 includes an oil pump control module 112, which may be included as part of an engine control module (ECM) 116. The oil pump control module 112 may control operation of a fixed, multiple, and/or variable displacement supply oil pump, such as oil pump assembly 120. The oil pump assembly 120 draws oil from a tank (e.g., dry sump, oil tank, etc.) and directs oil to components (e.g., valves, cylinders, camshafts, etc.) of the engine 108. An example sump is shown in FIGS. 2A and 2B. The oil pump control module 112 also controls operation of one or more variable displacement scavenge oil pump(s) 128 as described below in more detail.

The supply oil pump assembly 120 is mechanically connected to a crankshaft 124 of the engine 108. The supply oil pump assembly 120 may be a vane pump and/or gear pump. Oil flow output of the supply oil pump assembly 120 may be directly related to the rotating speed of the crankshaft 124 and is based on a control signal generated by the oil pump control module 112 and/or based on measured or calculated oil pressure at some location in the engine 108 such as oil pump outlet pressure, filter outlet pressure, or main gallery oil pressure. The supply oil pump assembly 120 may be located in a sump (e.g., oil pan) or elsewhere on the engine 108.

The engine 108 may also include one or more scavenge pumps 128. The oil pump control module 112 controls the scavenge pump 128 according to the principles of the present disclosure as described in more detail in FIGS. 2A and 2B. For example, the scavenge pump 128 may correspond to a variable displacement vane scavenge pump. Although one scavenge pump 128 is shown, implementations according to the principles of the present disclosure may include one or more of the scavenge pumps 128 to draw oil from the sump and/or other locations (i.e., collection points) within the vehicle (e.g., such as from cylinder heads, valleys, turbo assemblies, etc.). For example, a high performance vehicle may include 8 scavenge pumps. In one arrangement, a vehicle includes 2-4 scavenge pumps per oil pan and 1-2 pumps per cylinder head (e.g., one pump per pair of cylinders in an eight cylinder engine). While the engine 108 may include any number of cylinders, for illustration purposes a single representative cylinder 132 is shown. Although variable displacement vane scavenge pumps are described, any the principles of the present disclosure may be implemented with any suitable mechanism for varying scavenge pump ratios, including, but not limited to, vane, spur gear, or other variable displacement pumps, electric drive pumps with variable drive speeds, mechanical drive pumps with variable drive speeds, etc.

Referring now to FIGS. 2A and 2B, an example oil circulating control system 200 is shown. Solid lines between devices refer to oil lines or paths. Dashed lines between devices refer to electrical signal lines. The oil circulating control system 200 includes an oil pump control module 204, a supply oil pump assembly 208, and a sump (e.g., oil pan) 212. The supply oil pump assembly 208 includes a supply oil pump 216, which may correspond to a fixed displacement supply oil pump or, in some implementations, a variable displacement supply oil pump. The supply oil pump 216 provides oil to an engine 220.

The oil circulating control system 200 includes one or more scavenge pumps 224-1, 224-2, . . . , and 224-n, referred to collectively as scavenge pumps 224. In FIG. 2A, an example embodiment with multiple scavenge pumps 224 is shown. In FIG. 2B, an example embodiment with only a single scavenge pump 224 is shown. The scavenge pumps 224 draw oil from the sump 212 in one or more draw locations within the sump 212, and/or from one or more other draw locations 228 other than the sump 212, and provide the oil to a separate tank 232 (e.g., for de-aeration and subsequent pressurization of the oil circulating control system 200). The other draw locations 228 may include, but are not limited to, cylinder heads, valleys, turbo assemblies, etc. The dimensions of the tank 232 may be more suitable (e.g., than the sump 212) for facilitating withdrawal of the oil from the tank 232. For example, the tank 232 may be relatively tall and narrow. Oil is drawn from the tank 232 (e.g., by the supply oil pump 216 or another pump) and provided to the engine 220. In operation, engine oil in the sump 212 is drawn to the tank 232 by the scavenge pumps 224, and from the tank 232 to the supply oil pump assembly 208, where it is pressurized and directed to the engine 220. The engine oil is directed from the engine 220 back to the sump 212.

The oil pump control module 204 controls the supply oil pump assembly 208 and the scavenge pumps 224 based on engine operating parameters. The engine operating parameters may be determined based on signals from various sensors 236. The sensors 236 may include, but are not limited to, an engine speed sensor 240, an engine oil temperature (EOT) sensor 244, an engine coolant temperature sensor 248, an engine oil pressure (EOP) sensor 252, a vehicle accelerometer 260, an engine load sensor 264, and other sensors 268. For example, the other sensors 268 may include sensors to determine pitch, yaw, and/or roll of the vehicle, and sensors to determine lateral, longitudinal, and/or vertical accelerations of the vehicle. Although described as sensors, any of the sensors 236 can be implemented as, for example, models that calculate the various inputs based on other calculated and/or measured engine operating parameters. In other words, the engine parameters may be indirectly determined via corresponding algorithms instead of directly from sensors. For example, the ECM 104 may indirectly determine engine oil temperature via a corresponding algorithm based on engine operating conditions, states of the engine 220 and ambient conditions instead of directly from an EOT sensor.

The oil pump control module 204 controls the supply oil pump 216 and the scavenge pumps 224 by controlling respective solenoids 272 and 276-1, 276-2, . . . , and 276-n, referred to collectively as solenoids 276. For example, the oil pump control module 204 controls the pumps 224 by controlling duty cycles of the respective solenoids 276 and may control the supply oil pump 216 by controlling the duty cycle, voltage, and/or current of the solenoid 272. The oil pump control module 204 according to the principles of the present disclosure controls the scavenge pumps 224 based on, for example, engine speed, engine oil temperature, engine load, vehicle acceleration, and/or other engine operating parameters received from the sensors 236. For example, the oil pump control module 204 may control a scavenge ratio (i.e., a global, or overall, scavenge ratio) of a single pump, and/or may weigh respective scavenge ratios of multiple scavenge pumps based on an overall desired scavenge ratio.

Referring now to FIGS. 3 and 4, example oil circulation control systems 300 and 400, respectively, are shown. The oil control circulation system 300 according to the principles of the present disclosure includes an oil pan 304, a scavenge pump 308, an oil pump control module 312, and an oil conduit 316 to draw oil from the oil pan 304. The oil circulation control system 400 according to the principles of the present disclosure includes an oil pan 404, scavenge pumps 408-1, 408-2, . . . , and 408-n, referred to collectively as scavenge pumps 408, an oil pump control module 412, and oil conduits 416-1, 416-2, . . . , and 416-n, referred to collectively as oil conduits 416, for drawing oil from the oil pan 404 and one or more other draw locations 420 as described above with respect to FIGS. 1 and 2. The scavenge pumps 308 and 408 according to the principles of the present disclosure are variable displacement oil pumps implementing electronically controlled displacement (e.g., controlled via oil pump control modules 312 and 412, respectively). Accordingly, the variable displacement of the oil pumps 308 and 408 can be controlled (e.g., continuously or discretely) to increase the displacement when higher scavenge ratios are desired or decrease the displacement when lower scavenge ratios are desired.

In the oil circulation control system 300 (e.g., a system with a single pump 308 for drawing oil from the oil pan 304), the oil pump control module 312 determines a desired global (i.e., overall) scavenge ratio for the pump 308 based on engine speed, engine oil temperature, engine load, and vehicle acceleration. For example, vehicle acceleration in the longitudinal direction (e.g., from braking or forward acceleration) or the lateral direction (from vehicle turning) can cause oil in the oil pan 304 to shift. The vehicle acceleration may be sufficient to cause a significant decrease in an amount of the oil near an inlet of the conduit 316. Accordingly, it may be desirable to increase the scavenge ratio of the pump 308 when the vehicle acceleration indicates that the amount of the oil near the inlet of the conduit 316 is minimal. In other words, when the amount of oil near the inlet decreases, it is desirable to increase the scavenge ratio of the pump 308 to maximize the amount of oil recovered. Conversely, it may be desirable to decrease the scavenge ratio of the pump 308 when the vehicle acceleration indicates that the amount of the oil near the inlet of the conduit 316 is greater. In other words, when the amount of oil near the inlet increases, it may be desirable to decrease the scavenge ratio of the pump 308 because recovery of oil may be maintained at a desired rate even with a decreased scavenge ratio.

For example, the oil pump control module 312 may determine the scavenge ratio for the pump 308 based on other parameters (e.g., engine speed, engine oil temperature, engine load, etc.), and then modify the scavenge ratio based on a scavenge ratio multiplier (i.e., a multiplier based on the vehicle acceleration). The multiplier may be calculated, stored in a lookup table or multiplier map, etc. The oil pump control module 312 then controls the displacement of the pump 308 (e.g., by setting a duty cycle of a solenoid associated with the pump 308) according to the modified scavenge ratio.

In some implementations, the oil pump control module 312 may determine the scavenge ratio multiplier further based on measurements indicating an orientation of the vehicle relative to the driving surface (e.g., pitch, yaw, etc.). For example, the vehicle may include a gyroscope and/or other position sensing device (e.g. represented by other sensors 268 in FIG. 2) the measures the vehicle orientation and provides the measurements to the oil pump control module 312. Even absent vehicle acceleration, position of the vehicle due to terrain, a sloped driving surface, etc. can affect distribution of the oil in the oil pan 304. Accordingly, the oil pump control module 312 may determine the scavenge ratio multiplier further based on vehicle orientation measurements. The vehicle orientation measurements may be incorporated into the same scavenge ratio multiplier as the vehicle acceleration information, or may be used to calculate an independent scavenge ratio multiplier.

Conversely, in the oil circulation control system 400 (e.g., a system with multiple pumps 408-1 and 408-2 for drawing oil from the oil pan 404 and one or more optional pumps 408-n for drawing oil from other draw locations 420), the oil pump control module 412 may first determine an overall desired scavenge ratio (e.g., based on engine speed, engine oil temperature, engine load, and vehicle acceleration). The oil pump control module 412 then determines independent scavenge ratios for each of the pumps 408 based on the overall desired scavenge ratio vehicle, and further based on vehicle acceleration (e.g., longitudinal Gs lateral Gs corresponding to the vehicle acceleration) and/or vehicle orientation measurements (e.g., pitch, yaw, roll, etc.). For example, vehicle acceleration in the longitudinal direction (e.g., from braking or forward acceleration) can cause the oil in the oil pan 404 to shift forward (e.g., from braking, toward the front of the vehicle an inlet of the conduit 416-1 corresponding to the pump 408-1) or backward (e.g., from forward acceleration, toward the back of the vehicle and an inlet of the conduit 416-2 corresponding to the pump 408-2). Conversely, vehicle acceleration in the lateral direction can cause oil in the oil pan 404 to shift left (e.g., from turning right, toward the left of the vehicle and the inlet of the conduit 416-2) or right (e.g., from turning left, toward the right of the vehicle and the inlet of the conduit 416-1). Changes in the vehicle orientation (e.g., pitch, yaw) can cause the oil to shift forward, backward, left, and/or right in a similar manner. The vehicle acceleration and vehicle orientation may also cause the oil to shift in other draw locations 420.

Accordingly, the respective amounts of the oil located near the inlets of the conduits 416 changes with vehicle acceleration and/or orientation, and it may be desirable to increase the scavenge ratios of respective ones of the pumps 408 drawing oil from locations having an increased amount of oil while decreasing the scavenge ratios of respective ones of the pumps drawing oil from locations having a decreased amount of oil. In embodiments, the scavenge ratios may be limited according to a predetermined minimum (and/or maximum) scavenge ratio. For example, regardless of the overall desired scavenge ratio and the sensed operating conditions, a minimum scavenge ratio for the pumps 408 may be 10%. The individual scavenge ratios may be set to achieve a desired total scavenge pump displacement (i.e., an overall displacement of all of the scavenge pumps). For example, the total scavenge pump displacement may correspond to a sum of the displacements of all of the scavenge pumps at a given time.

For example, the oil pump control module 412 may determine the overall desired scavenge ratio for the pumps 408 and then modify respective scavenge ratios of the pumps 408 based on respective scavenge ratio multipliers. In other words, the oil pump control module 412 may determine a first scavenge ratio multiplier for the pump 408-1, a second scavenge ratio multiplier for the pump 408-2, and an nth scavenge ratio multiplier for the pump 408-n. The multipliers may be calculated, stored in a lookup table or multiplier map, etc. The oil pump control module 412 then controls the displacement of the pumps 408 (e.g., by setting a duty cycle of respective solenoids associated with the pumps 408) according to the modified scavenge ratios.

As described herein, “scavenge ratio” may be defined according to various relationships between the scavenge pumps and the supply oil pump. For example, variable displacement pumps used to implement the scavenge pumps may be configured to vary from a maximum volumetric displacement to a minimum (e.g., zero) volumetric displacement. Accordingly, an instantaneous displacement of any individual scavenge pump can vary from 100% to 0% of its respective maximum volumetric displacement.

In embodiments, a “maximum global scavenge ratio” may correspond to a sum of this maximum volumetric displacement of all of the scavenge pumps divided by the maximum displacement of the supply oil pump(s). For example, in a system with four scavenge pumps and one supply oil pump each with the same maximum volumetric displacement, the maximum global scavenge ratio for the collective scavenge pumps would be 4 to 1, or 400%.

Conversely, an instantaneous global scavenge ratio may correspond to a sum of the instantaneous displacements of all of the scavenge pumps (or the instantaneous displacement of the single scavenge pump in embodiments with only one scavenge pump) divided by the maximum displacement of the supply oil pump. An instantaneous individual scavenge ratio may correspond to a ratio of the instantaneous displacement of any one scavenge pump to the maximum displacement of the supply oil pump. The instantaneous individual scavenge ratios of respective pumps may be the same or may be different as described herein, and the sum of all of the instantaneous individual scavenge ratios at any given time corresponds to the instantaneous global scavenge ratio.

Those skilled in the art can appreciate that other characterizations or definitions of scavenge ratios as they relate to the controlled parameters of the scavenge pumps may be used without departing from the principles of the present disclosure.

Referring now to FIG. 5, an example scavenge ratio multiplier map 500 (e.g., implemented by the oil pump control module 312 or 412) is shown. For example, the multiplier map 500 corresponds to a single scavenge pump, and various implementations may include a plurality of the multiplier maps 500 for respective pumps. Further, the multiplier map 500 corresponds to a scavenge pump located toward the left rear of a draw location (e.g., a pump such as the pump 408-2 having a conduit 416-2 with an inlet located toward the left rear of the oil pan 404). Accordingly, as the vehicle accelerates in the forward direction and/or turns right, a scavenge ratio multiplier for the scavenge pump 408-2 increases. Conversely, as the vehicle decelerates (e.g., brakes) and/or turns left, the scavenge ratio multiplier for the scavenge pump 408-2 decreases.

Referring now to FIG. 6, an example scavenge ratio control method 600 for a single pump according to the principles of the present disclosure begins at 604. For example only, the oil pump control module 312 may implement one or more steps of the method 600. At 608, the method 600 determines one or more operating parameters of the vehicle, including, but not limited to, engine speed, engine oil temperature, engine load, vehicle acceleration, and/or vehicle orientation. For example, the oil pump control module 312 receives sensor signals from sensors 236 and/or calculates or models the operating parameters according to other known inputs. At 612, the method 600 determines a desired scavenge ratio (e.g., an overall/global scavenge ratio) for a scavenge pump (e.g., the scavenge pump 308). For example, the oil pump control module 312 determines a scavenge ratio, determines a scavenge ratio multiplier based on vehicle acceleration and/or orientation, and modifies the scavenge ratio according to the multiplier. At 616, the method 600 sets a solenoid duty cycle (e.g., corresponding to a desired displacement of the scavenge pump) according to the modified scavenge ratio. The method 600 may then end at 620.

Alternatively, the method 600 may implement an optional feedback loop at 624 and 628. At 624, the method 600 receives feedback corresponding to one or more operating parameters affected by the operation of the scavenge pump. For example, the feedback may include, but is not limited to, crankcase pressure, scavenge pump pressure, scavenge pump displacement, etc. At 628, the method 600 determines whether the modified scavenge ratio is suitable based on the feedback. For example, the oil pump control module 312 may compare the information in the feedback to desired values for the corresponding operating parameters. If true, the method 600 ends at 620. If false, the method 600 continues to 612 to modify the scavenge ratio.

Referring now to FIG. 7, an example scavenge ratio control method 700 for multiple pumps according to the principles of the present disclosure begins at 704. For example only, the oil pump control module 412 may implement one or more steps of the method 700. At 708, the method 700 determines one or more operating parameters of the vehicle, including, but not limited to, engine speed, engine oil temperature, engine load, vehicle acceleration, and/or vehicle orientation. For example, the oil pump control module 412 receives sensor signals from sensors 236 and/or calculates or models the operating parameters according to other known inputs. At 712, the method 700 determines an overall desired scavenge ratio for the vehicle. At 716, the method 700 determines other measurements indicating distribution of oil within various oil draw locations. For example, the oil pump control module 412 receives measurements related to vehicle acceleration (e.g., longitudinal Gs, lateral Gs, etc.) and/or vehicle orientation (e.g., pitch, yaw, etc.).

At 720, the method 700 determines, based on the measurements, respective scavenge ratio multipliers for the multiple pumps (e.g., the scavenge pumps 408) and applies the scavenge ratio multipliers to the pumps. For example, the oil pump control module 412 calculates the scavenge ratio multipliers based on the vehicle acceleration and/or orientation measurements, and modifies the scavenge ratio for each of the pumps according to the multiplier. At 724, the method 700 sets solenoid duty cycles (e.g., corresponding to desired displacements of the scavenge pumps) according to the respective modified scavenge ratios. The method 700 may then end at 728.

Alternatively, the method 700 may implement an optional feedback loop at 732 and 736. At 732, the method 700 receives feedback corresponding to one or more operating parameters affected by the operation of the scavenge pumps. For example, the feedback may include, but is not limited to, crankcase pressure, scavenge pump pressure, scavenge pump displacement, etc. At 736, the method 700 determines whether the modified scavenge ratios are suitable based on the feedback. For example, the oil pump control module 412 may compare the information in the feedback to desired values for the corresponding operating parameters. If true, the method 700 ends at 728. If false, the method 700 continues to 712 to modify the scavenge ratios.

In embodiments, the global scavenge ratio and/or individual pump scavenge ratios can be controlled in a closed-loop feedback fashion. For example, rather than relying only on the vehicle operating parameters as determined at 608/708, the systems 300/400 may determine the overall desired scavenge ratio based on direct indicators including, but not limited to, signals from oil pressure sensors, oil level sensors, etc.

Referring now to FIG. 8, an example scavenge ratio control method 800 using multiple scavenge ratio maps according to the principles of the present disclosure begins at 804. For example, the method 800 may operate according to a best torque map (which is based on maximizing crankshaft torque and therefore provides a scavenge ratio that maximizes torque while still meeting lubrication requirements, ventilation system requirements, etc.) and a best scavenging map (which is based on minimizing aeration, tank drawdown, etc.). The best torque map and the best scavenging map may be generated according to observations of the system at various engine speeds, load maps, oil temperatures, etc. (e.g., during dyno calibration).

At 808, the method 800 sets one or more scavenge ratios (e.g., as described in FIGS. 7 and 8) according to the best torque map. At 812, the method 800 corrects the scavenge ratios for barometric pressure. At 816, the method 800 determines whether lateral and/or longitudinal acceleration are greater than a threshold (e.g., 0.5 Gs). If true, the method 800 continues to 820. If false, the method 800 continues to 824. At 824, the method 800 determines whether engine oil temperature is greater than a threshold (e.g., 120° C.). If true, the method 800 continues to 820. If false, the method 800 continues to 828. At 828, the method 800 determines whether an amount of time using scavenge ratios from the best torque map is greater than a threshold (e.g., 100 seconds). If true, the method 800 continues to 820. If false, the method 800 continues to 808.

At 820, the method 800 sets the one or more scavenge ratios according to the best scavenging map. At 832, the method 800 corrects the scavenge ratios for barometric pressure. At 836, the method 800 determines whether an amount of time using scavenge ratios from the best scavenging map is less than a threshold (e.g., 10 seconds). If true, the method 800 continues to 820. If false, the method 800 continues to 840. At 840, the method 800 determines whether lateral and/or longitudinal acceleration are greater than a threshold (e.g., 0.5 Gs). If true, the method 800 continues to 820. If false, the method 800 continues to 844. At 844, the method 800 determines whether engine oil temperature is greater than a threshold (e.g., 120° C.). If true, the method 800 continues to 820. If false, the method 800 continues to 808.

The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical OR. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure.

In this application, including the definitions below, the term module may be replaced with the term circuit. The term module may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC); a digital, analog, or mixed analog/digital discrete circuit; a digital, analog, or mixed analog/digital integrated circuit; a combinational logic circuit; a field programmable gate array (FPGA); a processor (shared, dedicated, or group) that executes code; memory (shared, dedicated, or group) that stores code executed by a processor; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, such as in a system-on-chip.

The term code, as used above, may include software, firmware, and/or microcode, and may refer to programs, routines, functions, classes, and/or objects. The term shared processor encompasses a single processor that executes some or all code from multiple modules. The term group processor encompasses a processor that, in combination with additional processors, executes some or all code from one or more modules. The term shared memory encompasses a single memory that stores some or all code from multiple modules. The term group memory encompasses a memory that, in combination with additional memories, stores some or all code from one or more modules. The term memory may be a subset of the term computer-readable medium. The term computer-readable medium does not encompass transitory electrical and electromagnetic signals propagating through a medium, and may therefore be considered tangible and non-transitory. Non-limiting examples of a non-transitory tangible computer readable medium include nonvolatile memory, volatile memory, magnetic storage, and optical storage.

The apparatuses and methods described in this application may be partially or fully implemented by one or more computer programs executed by one or more processors. The computer programs include processor-executable instructions that are stored on at least one non-transitory tangible computer readable medium. The computer programs may also include and/or rely on stored data. 

What is claimed is:
 1. A system comprising: a first scavenge oil pump that draws oil from a first draw location within a vehicle according to a first variable displacement associated with the first scavenge oil pump, wherein the first variable displacement is based on a first modified scavenge ratio assigned to the first scavenge oil pump; and an oil pump control module that determines a first scavenge ratio, determines a first scavenge ratio multiplier based on at least one of vehicle acceleration and vehicle orientation, and that applies the first scavenge ratio multiplier to the first scavenge ratio to generate the first modified scavenge ratio.
 2. The system of claim 1, wherein the oil pump control module sets a first duty cycle of a first solenoid associated with the first scavenge oil pump based on the first modified scavenge ratio.
 3. The system of claim 1, wherein the vehicle orientation corresponds to at least one of pitch and yaw of the vehicle.
 4. The system of claim 1, wherein the first draw location corresponds to a location in an oil pan.
 5. The system of claim 1, wherein the oil pump control module determines the first scavenge ratio multiplier using a scavenge ratio multiplier map.
 6. The system of claim 1, wherein the oil pump control module determines the first scavenge ratio based on engine speed, engine oil temperature, and engine load.
 7. The system of claim 1, further comprising a second scavenge oil pump that draws oil from a second draw location within the vehicle according to a second variable displacement associated with the second scavenge oil pump, wherein the second variable displacement is based on a second modified scavenge ratio assigned to the second scavenge oil pump, and wherein the oil pump control module determines a second scavenge ratio multiplier based on the at least one of the vehicle acceleration and the vehicle orientation, and applies the second scavenge ratio multiplier to the first scavenge ratio to generate the second modified scavenge ratio.
 8. The system of claim 7, wherein the first draw location and the second draw location correspond to different locations within the vehicle.
 9. The system of claim 7, wherein the first scavenge ratio multiplier and the second scavenger ratio multiplier are different.
 10. A method comprising: using a first scavenge oil pump, drawing oil from a first draw location within a vehicle according to a first variable displacement associated with the first scavenge oil pump, wherein the first variable displacement is based on a first modified scavenge ratio assigned to the first scavenge oil pump; determining a first scavenge ratio; determining a first scavenge ratio multiplier based on at least one of vehicle acceleration and vehicle orientation; and applying the first scavenge ratio multiplier to the first scavenge ratio to generate the first modified scavenge ratio.
 11. The method of claim 10, further comprising setting a first duty cycle of a first solenoid associated with the first scavenge oil pump based on the first modified scavenge ratio.
 12. The method of claim 10, wherein the vehicle orientation corresponds to at least one of pitch and yaw of the vehicle.
 13. The method of claim 10, wherein the first draw location corresponds to a location in an oil pan.
 14. The method of claim 10, wherein determining the first scavenge ratio multiplier includes determining the first scavenge ratio multiplier using a scavenge ratio multiplier map.
 15. The method of claim 10, wherein determining the first scavenge ratio includes determining the first scavenge ratio based on engine speed, engine oil temperature, and engine load.
 16. The method of claim 10, further comprising, using a second scavenge oil pump, drawing oil from a second draw location within the vehicle according to a second variable displacement associated with the second scavenge oil pump, wherein the second variable displacement is based on a second modified scavenge ratio assigned to the second scavenge oil pump, determining a second scavenge ratio multiplier based on the at least one of the vehicle acceleration and the vehicle orientation, and applying the second scavenge ratio multiplier to the first scavenge ratio to generate the second modified scavenge ratio.
 17. The method of claim 16, wherein the first draw location and the second draw location correspond to different locations within the vehicle.
 18. The method of claim 16, wherein the first scavenge ratio multiplier and the second scavenger ratio multiplier are different. 